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991.
The technique of enzyme-linked immunosorbent assay (ELISA) was modified to enable detection of apple chlorotic leafspot virus (CLSV) both in herbaceous hosts and in several naturally infected fruiting and ornamental woody host species. Some of the characteristics of the modified method as used with different virus-host combinations are described.  相似文献   
992.
(+/-) Fenibut beta-phenyl-GABA) was not able to displace 3H-GABA in Na+ independent GABA binding (IC50 greater than 250 microM). Nevertheless, (+/-) fenibut and (+/-) baclofen effectively displaced 3H-GABA in Ca2+ dependent GABA binding in the presence of 50 microM (+) bicuculline. (+/-) Fenibut was less potent in this respect. It is suggested that fenibut may act via bicuculline-insensitive GABA receptors.  相似文献   
993.
The vertebrate head is an extremely complicated structure: development of the head requires tissue-tissue interactions between derivates of all the germ layers and coordinated morphogenetic movements in three dimensions. In this review, we highlight a number of recent embryological studies, using chicken, frog, zebrafish and mouse, which have identified crucial signaling centers in the embryonic face. These studies demonstrate how small variations in growth factor signaling can lead to a diversity of phenotypic outcomes. We also discuss novel genetic studies, in human, mouse and zebrafish, which describe cell biological mechanisms fundamental to the growth and morphogenesis of the craniofacial skeleton. Together, these findings underscore the complex interactions leading to species-specific morphology. These and future studies will improve our understanding of the genetic and environmental influences underlying human craniofacial anomalies.  相似文献   
994.
The Australian desert ant Melophorus bagoti often follows stereotypical routes through a cluttered landscape containing both distant panoramic views and obstacles (plants) to navigate around. We created an artificial obstacle course for the ants between a feeder and their nest. Landmarks comprised natural objects in the landscape such as logs, branches, and tussocks. Many ants travelled stereotypical routes home through the obstacle course in training, threading repeatedly the same gaps in the landmarks. Manipulations altering the relations between the landmarks and the surrounding panorama, however, affected the routes in two major ways. Both interchanging the positions of landmarks (transpositions) and displacing the entire landmark set along with the starting position of the ants (translations) (1) reduced the stereotypicality of the route, and (2) increased turns and meanders during travel. The ants might have used the entire panorama in view-based travel, or the distal panorama might prime the identification and use of landmarks en route. Despite the large data set, both options (not mutually exclusive) remain viable.  相似文献   
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